The World today faces a critical challenge as all nations strive to satisfy basic human requirements—food, shelter, clothing and work—that are so dependent on adequate supplies of energy. The great increase in the use of energy has been met mostly by fossil fuels—primarily, coal, oil and gas. The belief is that environmental concerns, security of supply, and economic impacts must all be balanced as the demand for energy continues to increase. Real economic growth and energy use nevertheless still remain inextricably linked.
While the quest for ultimate solutions to provide adequate energy supplies continues, near term, interim solutions must be considered for meeting the immediate growth in demand for energy. Technological improvements in the mining, drilling, moving, processing, and using of fossil fuels can, of course, stretch energy resource reserves, as can a determined effort at conservation of energy. Similarly, the utilization of advanced clean fossil fuel technologies involving the employment of various forms of hot solids processes such as, by way of exemplification and not limitation, fossil fuel gasification, fluidized-bed combustion, or hybrid combustion-gasification fossil fuel technologies are capable of having the effect of that of widening the use of the World's vast fossil fuel resources.
In accordance with the mode of operation of electrical power generation systems, as is well known to most, the steam that is produced by steam generators, which are employed in such electrical power generation systems, from the combustion of fossil fuel therein is designed to be employed in steam turbines. Such steam, which commonly is both at a high temperature and at a high pressure, is expanded in the aforementioned steam turbine in order to thereby effect a rotation of the steam turbine. Such rotation of the steam turbine in turn is operative in a known manner to cause a generator that is suitably operatively connected to the steam turbine to rotate as well. Then, when the generator undergoes such rotation, a conductor is made to move through a magnetic field thereby causing an electric current to be generated. The aforedescribed mode of operation is fundamentally the basis upon which electrical power generation systems continue to be predicated even to this day.
In an effort to realize higher efficiencies for electrical power generation systems, attempts have been known to have been made to increase the temperatures and the pressures at which the steam generators that are employed in such electrical power generation systems are capable of being operated. Such efforts to date have resulted in steam generators being supplied commercially for employment in electrical power generation systems that are capable of being operated at subcritical pressure conditions or that are capable of being operated at supercritical pressure conditions. Improvements in the strength of the materials from which such steam generators, which are intended for employment in electrical power generation systems, are designed to be constructed have permitted such materials, and thus such steam generators, to be operated both at such higher temperatures and at such higher pressures.
Discussing further the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed, and in particular to that of fossil fuel gasification technologies, attention is first directed in this connection, by way of exemplification and not limitation, to U.S. Pat. No. 2,602,809, which issued on Jul. 8, 1952 to The M. W. Kellogg Company. The teachings of U.S. Pat. No. 2,602,809 are considered to be representative of an exemplification of an early development in the continuing development of fossil fuel gasification technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 2,602,809 are directed to a process, which is said to be particularly suited for the gasification of low-grade solid carbon-containing materials. More specifically, insofar as the mode of operation of the process to which the teachings of U.S. Pat. No. 2,602,809 are directed is concerned, the solid carbon-containing materials are designed to be oxidized in order to convert such solid carbon-containing materials to carbon oxides by virtue of the indirect oxidation thereof with air in such a manner that the nitrogen of the air does not contaminate the product gas. Such gasification of the solid carbon-containing materials is accomplished by virtue of the alternate oxidation and reduction of a fluidized metal oxide. According to the teachings of U.S. Pat. No. 2,602,809, solid fuels are subjected to being converted to gases as a consequence of the contacting by a metal oxide with finely-divided solid carbon-containing materials under conditions such as to cause the metal oxide to be reduced and the carbon of the solid fuel to be oxidized to carbon oxides, with the metal oxide being the principal source of oxygen that is required for the oxidation of the carbon. Then, after the metal oxide has been reduced, the reduced metal oxide is subjected to being re-oxidized whereupon the process cycle is capable of being repeated once again.
With further regard to the fossil fuel gasification technologies of the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed, attention is next directed herein, by way of exemplification and not limitation, to U.S. Pat. No. 4,602,573, which issued on Jul. 29, 1986 to Combustion Engineering, Inc. The teachings of U.S. Pat. No. 4,602,573 are considered to be representative of an exemplification of a further development in the continuing evolution of fossil fuel gasification technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 4,602,573 are stated to be directed to a method of gasifying and combusting a carbonaceous fuel and, more particularly to an integrated process wherein a sulfur and nitrogen-bearing carbonaceous fuel is gasified to produce a carbon monoxide-rich low BTU fuel gas that is designed to be subsequently combusted with additional carbonaceous fuel in a steam generator. More specifically, insofar as the mode of operation of the process to which the teachings of U.S. Pat. No. 4,602,573 are directed is concerned, a first portion of sulfur and nitrogen-bearing carbonaceous fuel is gasified in a gasification reactor in a reducing atmosphere of air to produce a hot, char-containing, carbon monoxide-rich fuel gas having a low BTU content. Thereafter, a sulfur capturing material is introduced into the gasification reactor so that the gasifying of the carbonaceous fuel is carried out in the presence of the sulfur capturing material whereby a substantial portion of the sulfur in the carbonaceous fuel being gasified is captured by the sulfur capturing material.
Attention will next be directed herein further to the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed and in particular to that of fluidized-bed combustion technologies. Thus, more specifically, attention is therefore directed in this connection, by way of exemplification and not limitation, to U.S. Pat. No. 4,111,158, which issued on Sep. 5, 1978 to Metallgesellschaft Aktiengesellschaft. The teachings of U.S. Pat. No. 4,111,158 are considered to be representative of an exemplification of an early development in the continuing development of the fluidized-bed combustion technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 4,111,158 are stated to be directed to a method of and an apparatus for carrying out an exothermic process in which a solid feed contains a combustible such as, for example, carbonaceous or sulfurous compounds. Continuing, insofar as the mode of operation of the method of and the apparatus for to which the teachings of U.S. Pat. No. 4,111,158 are directed is concerned, the combustible compounds of the solid feed are designed to be burned under approximately stoichiometric conditions in a fluidized bed. Thereafter, the solids, which are produced as a consequence of such burning of the combustible compounds of the solid feed and which are withdrawn from the fluidized bed are caused to be recycled back to the fluidized bed, while the heat that is produced from such burning of the combustible compounds of the solid feed is available to be recovered.
Regarding further the fluidized-bed combustion technologies of the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed, attention is next directed herein, by way of exemplification and not limitation, to U.S. Pat. No. 5,533,471, which issued on Jul. 9, 1996 to A. Ahlstrom Corporation. The teachings of U.S. Pat. No. 5,533,471 are considered to be representative of an exemplification of a further development in the continuing evolution of fluidized-bed combustion technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 5,533,471 are stated to be directed to a system and to a method that allow the temperature of the fluidized bed reactor to be controlled efficiently, allowing adequate heat transfer surface area for cooling of solid materials. More specifically, insofar as the mode of operation of the system and of the method to which the teachings of U.S. Pat. No. 5,533,471 are directed is concerned, a circulating (fast) fluidized bed and a bubbling (slow) fluidized bed are utilized. Continuing, these two (2) fluidized beds are mounted adjacent each other with first and second interconnections between them, typically with the fluidizing gas introducing grid of the bubbling fluidized bed being below that of the circulating fluidized bed. Because the bubbling fluidized bed has a substantially constant density throughout, with a clear demarcation line at the top thereof, the first interconnection is provided above the top of the bubbling fluidized bed so that the pressure and density conditions between the two (2) fluidized beds result in a flow of particles from the circulating fluidized bed to the bubbling fluidized bed through the first interconnection. However, since the average density in the bubbling fluidized bed is higher than the density in the circulating fluidized bed, the pressure and density conditions cause the particles after treatment in the bubbling fluidized bed (e.g., after the cooling of the particles therein) to return to the circulating fluidized bed through the second interconnection.
Discussing further the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed, and in particular that of hybrid combustion-gasification technologies, attention is first directed in this connection, by way of exemplification and not limitation, to U.S. Pat. No. 4,272,399, which issued on Jun. 8, 1981 to the Monsanto Company. The teachings of U.S. Pat. No. 4,272,399 are considered to be representative of an exemplification of an early development in the continuing evolution of the hybrid combustion-gasification technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 4,272,399 are stated to be directed to a unified process for producing high purity synthesis gas from carbon-containing materials. More specifically, insofar as the mode of operation of the unified process to which the teachings of U.S. Pat. No. 4,272,399 are directed is concerned, a metal-oxygen containing material, which can be characterized as a heat and oxygen carrier and which can be referred generally as an oxidant, is used as the transfer agent of oxygen and heat for oxidatively gasifying carbon-containing material. Continuing, steam, carbon dioxide, synthesis gas or mixtures thereof are employed to fluidize and transport the oxidant through an up-flow, co-current system. Thus, in accordance with the mode of operation of the subject unified process, synthesis gas is first oxidized and heated by the oxidant to form water and carbon dioxide in an oxidant reducing zone prior to contact of the oxidant and gases with the carbon-containing material in a gasifying zone. In addition, the carbon-containing materials are oxidized to predominately carbon monoxide and hydrogen in a manner such that the nitrogen contained in the air does not contaminate the product synthesis gas. Furthermore, the gasification of the carbon-containing material is accomplished by the alternate oxidation and reduction of a fluidized oxidant. Then, after such gasification, the reduced oxidant, which may be in the form of the elemental metal or lower oxidized state is re-oxidized in an oxidizing zone and the cycle is then repeated.
Regarding further the hybrid combustion-gasification technologies of the advanced clean fossil fuel technologies to which reference has been had above previously wherein various forms of hot solids processes are employed, attention is next directed herein, by way of exemplification and not limitation, to U.S. Pat. No. 7,083,658, which issued on Aug. 1, 2006 to ALSTOM Technology Ltd., which is incorporated herein by reference. The teachings of U.S. Pat. No. 7,083,658 are considered to be representative of an exemplification of a further development in the continuing evolution of hybrid combustion-gasification technologies of the type wherein hot solids processes are employed. To this end, in accordance with the teachings thereof, the teachings of U.S. Pat. No. 7,083,658 are stated to be directed to apparatus utilizing fossil fuels, biomass, petroleum coke, or any other carbon bearing fuel to produce hydrogen for power generation, which minimizes or eliminates the release of carbon dioxide (CO2). More specifically, insofar as the mode of operation of the apparatus to which the teachings of U.S. Pat. No. 7,083,658 are directed is concerned, a gasifier is provided for producing a gas product from a carbonaceous fuel, which comprises a first chemical process loop including an exothermic oxidizer reactor and an endothermic reducer reactor. Continuing, the exothermic oxidizer reactor has a CaS inlet, a hot air inlet and a CaSO4/waste gas outlet. Whereas, the endothermic reducer reactor has a CaSO4 inlet in fluid communication with the exothermic oxidizer reactor CaSO4/waste gas outlet, a CaS/gas product outlet in fluid communication with the exothermic oxidizer reactor CaS inlet, and a materials inlet for receiving the carbonaceous fuel. Moreover, CaS is oxidized in air in the exothermic oxidizer reactor to form hot CaSO4, which is discharged to the endothermic reducer reactor. Furthermore, hot CaSO4 and carbonaceous fuel that is received in the endothermic reducer reactor undergo an endothermic reaction utilizing the heat content of the CaSO4 with the carbonaceous fuel stripping the oxygen from the CaSO4 to form CaS and the gas product. Thereafter, the CaS is discharged to the exothermic oxidizer reactor, and with the gas product being discharged from the first chemical process loop.
It is, therefore, an object of the present invention to provide a hot solids process that is selectively operable based on what the specific nature of the hot solids process' primary purpose is.
It is also an object of the present invention to provide such a hot solids process that is capable of being selectively operated for purposes of generating at least one predetermined output.
It is another object of the present invention to provide such a hot solids process that is capable of being selectively operated based on what the specific nature of the hot solids process' primary purpose is for which at least one predetermined output is being produced for purposes of generating such a predetermined output.
It is still another object of the present invention to provide such a hot solids process, which is capable of being selectively operated for purposes of generating at least one predetermined output based on what the specific nature of the hot solids process' primary purpose is for which the at least one predetermined output is being produced, and wherein such hot solids process' primary purpose is designed to be pre-selected from a group of hot solids process' primary purposes.
A further object of the present invention is to provide such a hot solids process that is capable of being selectively operated for purposes of generating at least one predetermined output based on what the specific nature of the hot solids process' primary purpose is for which such at least one predetermined output is being produced, and wherein such hot solids process' primary purpose is designed to be pre-selected from a group of hot solids process' primary purposes included in which are H2 for electric power production, SynGas for electric power generation as well as for other industrial uses, steam production for electric power generation as well as for other uses, process heat production, CO2 production for agricultural purposes, and a feedstock such as, by way of exemplification and not limitation, H2 for use for liquid hydrocarbons production.
Yet another object of the present invention is to provide such a hot solids process that is relatively inexpensive to provide, that is relatively uncomplicated to employ, and that is characterized by the great versatility, which such a hot solids process embodies insofar as concerns the hot solids process' primary purpose for which at least one predetermined output, which it is desired to produce for such a hot solids process' primary purpose, is capable of being generated through the use of the hot solids process of the present invention.